Abstract
As acute stroke therapies have developed, the context in which stroke care is provided has become more important. Creating and maintaining the organization of stroke care within a region or even a hospital requires much commitment and effort. High-quality stroke care requires coordination and communication between multiple stakeholders in the prehospital and in-hospital settings in what the American Heart Association (AHA) and American Stroke Association (ASA) term the “stroke chain of survival” (Table 14.1).
As acute stroke therapies have developed, the context in which stroke care is provided has become more important. Creating and maintaining the organization of stroke care within a region or even a hospital requires much commitment and effort. High-quality stroke care requires coordination and communication between multiple stakeholders in the prehospital and in-hospital settings in what the American Heart Association (AHA) and American Stroke Association (ASA) term the “stroke chain of survival” (Table 14.1).1 An ASA task force offers a set of recommendations on systems of stroke care.2, 3 The European Stroke Initiative also provides a good set of evidence-based recommendations.4–6
Detection | Patient or bystander recognition of stroke signs and symptoms |
Dispatch | Immediate activation of 9-1-1 and priority EMS dispatch |
Delivery | Prompt triage and transport to most appropriate stroke hospital and prehospital notification |
Door | Immediate ED triage to high-acuity area |
Data | Prompt ED evaluation, stroke team activation, laboratory studies, and brain imaging |
Decision | Diagnosis and determination of most appropriate therapy; discussion with patient and family |
Drug | Administration of appropriate drugs or other interventions |
Disposition | Timely admission to stroke unit, intensive care unit, or transfer |
ED, emergency department; EMS, emergency medical services.
Timely Care
Time is a crucial factor in improving stroke outcomes. Most investigational therapies for hemorrhagic stroke are also focused on early interventions. Treatments for acute ischemic stroke (AIS) are time-sensitive. Intravenous tPA must be given within 4.5 hours. Endovascular thrombolysis (EVT) must be initiated within 6 hours for most patients, with imaging-selected patients eligible up to 24 hours. Both IV tPA and EVT for AIS are most effective when initiated early, and ideally within the first hour of symptoms onset.7, 8 However, only 3–9% of AIS patients receive IV thrombolysis and far fewer EVT, which is due to a combination of delays in recognition of stroke symptoms, activation of EMS, prehospital triage, and in-hospital stroke expertise.9–11 Therefore a focus on expediting prehospital stroke care is key.
Prehospital Stroke Care
Promotion of public awareness – Patients, families, and the general public must be educated regarding stroke symptom recognition, available stroke therapies, and the importance of emergency medical care. Several studies have demonstrated an increase in stroke symptom knowledge and readiness to call 911 through dynamic educational interventions with both children and adults.12–14
Mobile stroke units – The concept of a mobile stroke unit (MSU) to expedite prehospital evaluation and treatment of acute stroke patients was first developed in the early 2000s in Homberg/Saarland, Germany.15 An MSU is a specialized stroke ambulance equipped with a CT scanner for on-board brain imaging, laboratory testing, either an on-board or remote (via telemedicine) vascular neurologist, tPA, and commonly administered medications. There are more than 20 MSUs now worldwide, with an ongoing comparative effectiveness trial led by investigators in Houston, Texas, evaluating prehospital IV tPA treatment with MSU compared to standard in-hospital care.16
Partnership with prehospital providers – Dispatch personnel, ambulance drivers, emergency medical technicians, paramedics, and their medical supervisors must agree to prioritize acute stroke and train to increase stroke recognition. Acute stroke patients must be evaluated in a timely fashion, and preferentially transported to a stroke center if one is available. Ideally, prehospital providers pre-notify the receiving facility or stroke team directly and shorten the time to evaluation. ED physicians should evaluate immediately upon patient arrival. Stroke team members should be notified at the earliest time possible.
Prehospital Stroke Scales
In order for patients to receive the appropriate treatment quickly they must be transported to a hospital that can provide acute stroke care including IV thrombolysis and in the case of large-vessel occlusion (LVO) also EVT.
Several prehospital stroke scales have been utilized by medics in the field to help identify patients who are more likely to have had a stroke. The most studied of these scales are the Cincinnati Prehospital Stroke Severity Scale (CPSSS), the Los Angeles Motor Scale (LAMS), and the Rapid Arterial Occlusion Evaluation (RACE) (Table 14.2). In a prehospital scale that aims to predict LVO, cortical signs (speech difficulty, gaze deviation, and neglect) may be more sensitive than motor deficits.17
No. of patients | No. of items | Items | Cutoff | Need to calculate score | SENS | SPEC | ACC | |
---|---|---|---|---|---|---|---|---|
3-ISS | 171 | 3 | Level of consciousness Gaze deviation Motor function | ≥ 4 | Yes | 0.67 | 0.92 | 0.86 |
CPSSS | 303 | 3 | Level of consciousness Gaze deviation Arm weakness | ≥ 2 | Yes | 0.83 | 0.40 | 0.67 |
FAST-ED | 727 | 6 | Facial palsy Arm weakness Speech changes Eye deviation Denial/neglect | ≥ 4 | Yes | 0.60 | 0.89 | 0.79 |
LAMS | 94 | 3 | Facial palsy Arm drift Grip strength | ≥ 4 | Yes | 0.69 | 0.81 | 0.77 |
RACE | 357 | 6 | Facial palsy Arm motor function Leg motor function Head and gaze deviation Aphasia Agnosia | ≥ 5 | Yes | 0.85 | 0.68 | 0.82 |
PASS | 3127 | 3 | Level of consciousness Gaze palsy/deviation Arm weakness | ≥ 2 | Yes | 0.66 | 0.83 | 0.74 |
VAN | 62 | 4 | Arm weakness Visual disturbance Aphasia Neglect | No | No | 1.0 | 0.90 | 0.92 |
Drip-and-Ship versus Mothership Models
Currently, in most major cities, the “drip-and-ship” model of care is utilized, in which eligible AIS patients are transported to the nearest hospital, treated with IV tPA, and then transferred to a high-volume tertiary center for EVT evaluation and ongoing acute stroke care.25 In the “mothership” model of care, patients with suspected LVOs are transported directly from the field by EMS to EVT-capable centers.26 Observational registry data suggest that the drip-and-ship model may be associated with delayed treatment and worse outcomes in patients who require interhospital transfer. The ongoing prospective randomized RACECAT in Barcelona, Spain, is comparing the drip-and-ship versus mothership models of care for AIS patients with suspected LVO.27
Stroke Centers
Whenever possible, stroke patients should be treated in hospitals with the ability to deliver acute stroke treatments quickly and efficiently. It is important to foster the development of such “stroke centers.” This may involve the need to establish a regional organization of stroke care.
Primary stroke centers (PSCs) are hospitals that have sufficient medical providers, protocols, and facilities to provide good basic acute stroke care, with acute stroke teams, stroke units, and ability to administer IV TPA. In the USA the Brain Attack Coalition has published criteria for PSCs,28 and the Joint Commission on Accreditation of Healthcare Organizations started accreditation of primary stroke centers in December 2003.29
Comprehensive stroke centers have advanced capability with availability of interventionalists and neurosurgeons. Quality-assurance measures such as written protocols and performance measurements should be part of stroke centers.
Telemedicine for Stroke (Telestroke)
In hospitals where physicians with expertise in stroke are not available, especially in rural areas where they are often many miles away, consultation by telephone or preferably real-time video conference system (telemedicine) allows safe administration of thrombolytics locally. It also can help identify appropriate patients requiring transfer to a comprehensive stroke center. Telemedicine is more accurate (> 95% accuracy) in diagnosing stroke and tPA eligibility than telephone (75%).30 Implementation of hyperacute telemedicine for stroke (telestroke) consultations by a vascular neurologist increases the use of IV tPA at community hospitals, with no difference in complication rates as compared to in-person consultation.31, 32